/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/MeshTangents.h
Get tangent and bitangent at a vertex of a triangle for per-triangle computed tangents
template<typename OtherVectorType> void GetTriangleVertexTangentVectors ( int32 TriangleID, int32 TriVertexIndex, OtherVectorType & TangentOut, OtherVectorType & BitangentOut ) const